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Improved Particle Swarm Optimization for Parameter Identification of Permanent Magnet Synchronous Motor

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Computers, Materials & Continua 2024年第5期79卷 2187-2207页

作者： Shuai zhou Dazhi Wang Yongliang ni Keling Song Yanming Li School of Information Science and Engineering Northeastern UniversityShenyang110819China China Northern Vehicle Research Institute Beijing100072China

In the process of identifying parameters for a permanent magnet synchronous motor,the particle swarm optimization method is prone to being stuck in local optima in the later stages of iteration,resulting in low parameter *** work proposes a fuzzy particle swarm optimization approach based on the transformation function and the filled *** approach addresses the topic of particle swarmoptimization in parameter identification from two ***,the algorithm uses a transformation function to change the form of the fitness function without changing the position of the extreme point of the fitness function,making the extreme point of the fitness function more prominent and improving the algorithm’s search ability while reducing the algorithm’s computational ***,on the basis of themulti-loop fuzzy control systembased onmultiplemembership functions,it is merged with the filled function to improve the algorithm’s capacity to skip out of the local optimal *** approach can be used to identify the parameters of permanent magnet synchronous motors by sampling only the stator current,voltage,and speed *** simulation results show that the method can effectively identify the electrical parameters of a permanent magnet synchronous motor,and it has superior global convergence performance and robustness.

关键词： Transformation function filled function fuzzy particle swarm optimization algorithm permanent magnet synchronous motor parameter identification

Low-field NMR micro coils based on printed circuit board technology

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Science China(Technological Sciences) 2014年第10期57卷 2082-2088页

作者： WU WeiPing LU RongSheng zhou XinLong ZHANG YunYi ni ZhongHua Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments Southeast University School of Mechanical Engineering Southeast University

Radiofrequency coil is one of the most important components for a nuclear magnetic resonance(NMR)*** this article,some planar micro coils with an inner diameter of 2 mm and number of turns that varied from 1 to 11 were investigated based on the printed circuit board(PCB)*** electrical characterization of micro coils show that self-resonant frequencies are larger than 200 ***,an NMR measurement platform with a static magnetic field of 0.66 T was constructed and the signal to noise ratio(SNR)values of the NMR were *** was found that the SNR is optimal when the turn number of the micro coils is six and the excitation time of a 90°pulse is 0.8?***,we used the micro coil with six turns to study the transverse relaxation rate of copper sulfate pentahydrate aqueous solution with different *** was found that the transverse relaxation rate is proportional to the solution *** from the micro coil were verified by measurements using a Bruker Minispec MQ60.

关键词： printed circuit board planar micro coil low-field nuclear magnetic resonance signal to noise ratio transverse relaxation rate

Molecular evolution of nitrogen-containing compounds in highly mature organic matter: Implications for the hydrocarbon generation potential

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Science China Earth Sciences 2023年第4期66卷 781-796页

作者： Jingkun ZHANG Jian CAO Wenxuan HU Baoli XIANG ni zhou Wanyun MA School of Earth Sciences and Engineering MOE Key Laboratory of Surficial GeochemistryNanjing UniversityNanjing 210023China Research Institute of Experiment and Testing PetroChina Xinjiang Oilfield CompanyKaramay 834000China

Evaluating the hydrocarbon generation potential of highly mature organic matter is a key and critically challenging area of research in petroleum geochemistry. To explore this issue, we used negative ion electrospray ionization-Fourier transform-ion cyclotron resonance-mass spectrometry to investigate the molecular evolution of N-containing compounds in Carboniferous-lower Permian source rocks with a range of maturities in the northwestern Junggar Basin, China. The N1compounds formed from on-fluorescent chlorophyll catabolites(NCCs), which record the characteristics of the residual soluble organic matter. These components remain in the source rocks after hydrocarbon generation and expulsion, and enable evaluation of the hydrocarbon generation potential. The newly defined indexes of molecular evolution, which are the polymerization index P1([DBE 18+DBE 15]/[DBE 12+DBE 9]_N1) and alkylation index R1(RC_(6–35)/RC_(0–5)), combined with the vitrinite reflectance(VR_(o)) and paleo-salinity index(β-carotane/n Cmax), can identify the factors that control the evolution of highly mature organic matter. The main factor for source rocks deposited in a weakly saline environment is the maturity, but for a highly saline environment both the maturity and salinity are key factors. The high salinity inhibits the molecular polymerization of organic matter and extends the oil generation peak. Given the differences in the bio-precursors in saline source rocks, we propose a new model for hydrocarbon generation that can be used to determine the oil generation potential of highly mature organic matter.

关键词： Negative ion ESI-FT-ICR-MS N-containing compound Residual hydrocarbon generation potential Highly mature organic matter Deep oil-gas Junggar Basin

Stress field modeling of northwestern South China Sea since 5.3 Ma and its tectonic significance

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Acta Oceanologica Sinica 2013年第12期32卷 31-39页

作者： YANG Fengli zhou Zuyi ZHANG Na LIU ning ni Bin School of Ocean and Earth Science Tongji University

Tectonically,the northwestern South China Sea(SCS)is located at the junction between three micro-plates,i.e.,the Indochina,South China and Zhongsha-Xisha micro-plates,and involves three basins,i.e.,the Yinggehai Basin,the Qiongdongnan Basin and Xisha Trough in the east,and the Zhongjiannan Basin in the *** the Pliocene(5.3 Ma),the Yinggehai Basin has experienced repeated accelerating subsidence,high thermal fluid,and widely developing mud-rich overpressure chambers,abundant mud diapers and crust-mantle mixed *** a large central canyon was developed in the Qiongdongnan Basin,new rift occurred in the Xisha *** characteristics demonstrate a single tectonic unit for the northwestern SCS,for which we have undertaken stress field modeling to understand its plate deformations and sedimentary *** results demonstrate that an extension tectonic event occurred after 5.3 Ma in the Yinggehai-Qiongdongnan-Xisha trough area,which is characterized by thinner crust(3 500 m).A new rift system subsequently was developed in this area;this event was mainly driven by the combined effects of different movement velocity and direction of the three micro-plates,and the far-field effect of the continental collision between the Indian Plate and the Tibetan Plateau,and subduction of the Pacific Plate underneath the Eurasian Plate.

关键词： northwestern South China Sea Pliocene stress field modeling rift system

A super-resolution algorithm for synthetic aperture radar based on modified spatially variant apodization

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Science China(Physics,Mechanics & Astronomy) 2011年第2期54卷 355-364页

作者： ni Chong WANG YanFei XU XiangHui zhou ChangYi CUI PengFei Institute of Electronics Chinese Academy of SciencesBeijing 100190 China Graduate University of the Chinese Academy of Sciences Beijing 100190 China

The existing spatially variant apodizations(SVAs) either cannot depress the sidelobes effectively or reduce the energy of the *** improve this,a modified SVA(MSVA) is put forward in this paper,which expands the traditional filter from 3-taps to 5-taps and sets relevant parameters according to different sampling rates to get the excellent result that satisfies constrained optimization theory.A modified super-SVA is also presented,which compares the result after the iteration with the original signal and makes the one whose amplitude is smaller as the initial value of the next *** method can eliminate the sidelobes produced by the intermediate operation,so that the following bandwidth extrapolation is more ***-MSVA is presented based on the modified SVA and modified super-SVA,which is suitable for any Nyquist sampling rate,can extrapolate the signal bandwidth many times through iteration with a commensurate improvement in resolution,as demonstrated by the result of the experiment.

关键词： synthetic aperture radar sidelobe suppression super-resolution SVA

Rapid Recognition of Isomers of Monochlorobiphenyls at Trace Levels by Surface-Enhanced Raman Scattering Using Ag Nanorods as a Substrate

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Nano Research 2010年第6期3卷 423-428页

作者： Qin zhou Ye Yang Jie ni Zhengcao Li Zhengjun Zhang Advanced Materials Laboratory Department of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

Isomers and homologues of organic pollutants are hard to distinguish-especially in trace amounts-due to the similarities in their physical and chemical properties. We report here that by identifying the Raman characteristics of isomers of monochlorobiphenyls, these compounds can be recognized, even at trace levels, by using the surface-enhance Raman scattering method with silver nanorods as a substrate. When dissolved in acetone, 2-, 3-, and 4-chlorobiphenyls were detected at a concentration of 10^(-8) mol/L, at which their characteristic Raman peaks were visible. This study may provide a fast, simple, and sensitive method for the detection and recognition of organic pollutants such as polychlorinated biphenyls.

关键词： Recognition isomer chlorobiphenyl trace levels SERS

Ensuring User Privacy and Model Security via Machine Unlearning: A Review

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Computers, Materials & Continua 2023年第11期77卷 2645-2656页

作者： Yonghao Tang Zhiping Cai Qiang Liu Tongqing zhou Qiang ni College of Computer National University of Defense TechnologyChangsha410073China School of Computing and Communications Lancaster UniversityEnglandB23UK

As an emerging discipline,machine learning has been widely used in artificial intelligence,education,meteorology and other *** the training of machine learning models,trainers need to use a large amount of practical data,which inevitably involves user ***,by polluting the training data,a malicious adversary can poison the model,thus compromising model *** data provider hopes that the model trainer can prove to them the confidentiality of the *** will be required to withdraw data when the trust *** the meantime,trainers hope to forget the injected data to regain security when finding crafted poisoned data after the model ***,we focus on forgetting systems,the process of which we call machine unlearning,capable of forgetting specific data entirely and *** this paper,we present the first comprehensive survey of this *** summarize and categorize existing machine unlearning methods based on their characteristics and analyze the relation between machine unlearning and relevant fields(e.g.,inference attacks and data poisoning attacks).Finally,we briefly conclude the existing research directions.

关键词： Machine learning machine unlearning privacy protection trusted data deletion

Analyzing crude oils from the Junggar Basin(NW China) using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry(GC×GC-TOFMS)

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Acta Geochimica 2017年第1期36卷 66-73页

作者： Yuce Wang Wanyun Ma ni zhou Jiangling Ren Jian Cao State Key Laboratory for Mineral Deposits Research Department of Earth SciencesNanjing University Research Institute of Experiment and Testing PetroChina Xinjiang Oilfield Company

As a new technology of analyzing crude oils, comprehensive two-dimensional gas chromatography cou- pled with time-of-flight mass spectrometry （GCxGC- TOFMS） has received much research attention. Here we present a case study in the Junggar Basin of NW China. Results show that the hydrocarbons, including saturates and aromatics, were all well-separated without large co- elution, which cannot be realized by conventional one-dimensional GC-MS. The GC×GC technique is especially effective for analyzing aromatics and low-to-middle- molecular-weight hydrocarbons, such as diamondoids. The geochemical characteristics of crude oils in the study area were investigated through geochemical parameters extracted by GC×GC-TOFMS, improving upon the understanding obtained by GC-MS. Thus, the work here represents a new successful application of GC×GC- TOFMS, showing its broad usefulness in petroleum geochemistry.

关键词： Comprehensive two dimensional gas chromatography coupled with time of flight mass spectrometry (GCxGC TOFMS) Petroleum geochemistry Biomarkers Diamondoid Junggar Basin

Monoradically luminescent polymers by a super acid-catalyzed polymerization and deep-red electroluminescence

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Science China Chemistry 2020年第9期63卷 1214-1220页

作者： Kebin An Guohua Xie Shaolong Gong Zhanxiang Chen Xiang zhou Fan ni Chuluo Yang Hubei Key Lab on Organic and Polymeric Optoelectronic Materials Department of ChemistryWuhan UniversityWuhan 430072China Shenzhen Key Laboratory of Polymer Science and Technology College of Materials Science and EngineeringShenzhen UniversityShenzhen 518060China

Luminescent radicals have received great attention recently due to their idiographic luminescent properties and potential 100%utilization efficiency of doublets under electrical ***,luminescent radical polymers are rarely explored owing to their challenging molecular design and ***,we report an efficient approach to construct luminescent radical polymers by a super acid-catalyzed polymerization reaction proceeded at room temperature,which intrinsically avoid the heavy metal *** obtained polymers exhibit the unique paramagnetic signals,good thermal properties,and excellent ***,the quantifiable electroluminescence of such radical polymers was demonstrated for the first time.

关键词： super acid-catalyzed polymerization doublets polymers electroluminescence organic light-emitting devices